Fertilizing should be done when pruning is done to stimulate growth in the spring. A lot of plant like good blood & bone. A lot of blood & bone in not good as it has a lot of other thing that do not feed the tree plant etc. The general rule is the ones that go hard are the good one the rest have something added. I use one that goes hard. Citrus need to be fed four times a year & generally need a lot of water more than most people do not give citrus enough water if in doubt talk to me for advice on this as you may also over water or have one of the other pest or diseases associated.
there are also a lot of mulches that also have fertilizer in them or carry nutrient value which are just as good my advice is wait till after the rain has stopped then lay mulch this enables the rain to get into the soil. By adding it now the mulch can in most instances absorb the moisture & rob the plant of the moisture so wait. when you are pruning pull out the weeds, fertilize, mulch.